A number of fasteners are known in which blind fastening occurs, particularly in the automotive industry as found in the assembly of instrument panels, bumpers, and the like. Such assemblies are typically carried out either by hand, or through use of automated equipment, with the above assembly process typically involving the interconnection of a pair of panel-like sections having edges which are placed in abutting or adjoining contact with one another. A pushnut or other fastener interconnecting the panels is used to complete the assembly.
Certain concerns have been voiced with regard to the inadequacy of the assembly process as well as ergonomic issues in relation to current fasteners. First, known pushnut fasteners present difficulties during installation. That is, the fastener is not easily fitted into a panel hole. Second, known fasteners have been prone to stripping problems during assembly, requiring expensive rework costs and perhaps more critically, creating assembly down time.
Third, known insert type fasteners such as those described in U.S. Pat. Nos. 4,925,351, 4,300,865; and 4,595,325 cannot create a sufficient clamp force due to a single threaded design. As a result, an inserted threaded male fastener can become loose during service due to shock and vibration.